1. Field of Invention
The present invention relates to an exhaust system of a diesel engine automobile, and in particular to an automobile urea tank and a forming method thereof.
1. Related Art
In order to protect ambient air quality, many countries in the world have introduced laws and regulations to control automobile exhaust. The automobile industry is more concerned about the environmental pollution caused by the exhaust emission. Regulations that strictly limit pollutant emission values are introduced one after another, and the emission requirement on nitrogen oxide is especially strict. With the implementation of EUR06, the emission limit for the nitrogen oxide is reduced to 0.07 g/km. Therefore, main engine plants have launched different new technologies for reducing exhaust emission, including the Selective Catalytic Reduction (abbreviated as SCR) technology. With this technology, the automobile urea solution Adblue is ejected into a specific reduction apparatus in the exhaust pipe and is subject to a chemical reaction with NOx, and finally NOx is converted into nitrogen and water that do not produce any pollution, and exhausted.
In an SCR technology system, the reducing agent Adblue is mainly stored in a plastic tank body, while Adblue storage tanks currently available on the market are mainly formed through blow molding. The SCR tank body formed through the blow molding process has high cost. The price of a blow molding device is more than ten times of that of an injection molding device, which increases the amortization of each tank body; secondly, the Adblue storage tank for automobiles has a small volume, while it is not easy to control the wall thickness of the tank body and the uniformity of the wall thickness in the blow molding process, which usually results in an excessive wall thickness, causing a waste of raw materials. The blow molded product has a lot of surplus fins at the periphery, which wastes a lot of raw materials. Moreover, in the blow molding process, built-in elements in the tank body are limited; for example, the design of the large part baffle is restricted by the diameter of the outer tank body in the blow molding process. Therefore, it is of urgent necessity to find a new method to solve the above technical problems.